1. Field of the Invention
The present invention relates to systems and methods for anchoring pipelines. More particularly, the present invention the relates to systems and methods for anchoring a pipeline wherein the pipeline is effectively isolated from the transmission line. Additionally, the present invention relates to subsea piles having a tensioning mechanism thereon so as to apply a tension force to the pipeline.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
During the production of oil and gas in offshore locations, wells are drilled in various locations in the subsea location. Each of these wells produces a quantity oil and/or gas. Ultimately, the oil and/or gas produced from each of the wells is delivered by various flow lines to the production platform. Ultimately, at the production platform, the gas is transmitted along a gas transmission line to the main pipeline. Conventionally, the gas line is connected to the main gas transmission line through the use of pipeline end termination assembly (PLET).
There are a variety of operations carried out at the subsea location. Often, these pipelines can be in the order of several miles of length. Under certain circumstances, a pipe can be snagged by an anchor, a dredge, or other obstacle. As a result, extreme forces may be applied to the pipeline. Ultimately, when these extreme forces are applied to the pipeline, the pipeline will separate from the PLET in a very damaging manner. Ultimately, this can cause a dislocation of the jumper spool which extends from the PLET to the main transmission line. As a result, expensive repairs are required to the PLET and, possibly, to the gas transmission line. As such, it is important to be able to isolate the gas pipeline from the gas transmission line so as to avoid such problems.
Ultimately, the damaged PLET must be raised to the surface of the body and repaired. Expensive procedures would then be required so as to reinstall the PLET in the subsea location and connect the damaged pipeline back to the PLET. This is a time consuming and very expensive process. As such, a need has developed whereby damage to the PLET is effectively prevented in those circumstances extreme forces are applied to the pipeline.
In the past, various patents have issued with respect to anchoring system for pipelines. Unfortunately, none of these anchoring systems effectively prevent the extreme forces that may be applied to the pipeline from adversely affecting the PLET and adversely affecting the connection with the gas transmission line. For example, U.S. Pat. No. 3,841,106, issued on Oct. 15, 1974 to R. Blumberg, shows a pipeline anchoring system for anchoring an underwater pipeline to the floor of a body of water. The anchor includes elongated members having an inverted U-shaped configuration. An underwater sled is disposed over a pipeline and aligned vertically with respect to a boat. Guide cables between the boat and sled permit lowering of an anchor and its embedment into the floor. Upon setting of an anchor, the buoyancy of the sled is increased and the sled is pulled to a new anchoring location by means of cables attached to the forward end of the sled.
U.S. Pat. No. 4,175,620, issued on Nov. 27, 1979 to Nolan, Jr. et al., teaches a method and apparatus for anchoring an offshore pipeline. The offshore pipeline installation includes a wellhead base and a pipeline anchor connected thereto to form a unit which is lowered onto a seabed. The anchor is pivotably positionable relative to the wellhead base about a vertical axis of a pilot tube. A pin pile is inserted through the tube and into the seabed to isolate the pipeline anchor from the wellhead and wellhead base in relation to forces generated in anchoring a pipeline to the pipeline anchor. The anchor is selectively positionable for alignment with pipeline means to be laid. A socket is operable to receive pipeline means laid away from the anchor.
U.S. Pat. No. 5,730,552, issued on Mar. 24, 1998 to Johannesson et al., shows a pipeline anchor apparatus that provides left and right anchor units with a tie-down strap. The strap prevents the pipeline from floating in wet conditions.
U.S. Pat. No. 6,132,141, issued on Oct. 17, 2000 to W. D. Kirk, provides a pipeline buoyancy control assembly and tie-down attachment. Anchor rods are driven partially into the ground along opposite lateral sides of the pipeline. The tie-down attachment members are disposed on and mounted to upper end portions of the anchor rods with each tie-down attachment member having a tubular mounting body defining an axial passageway through which the upper end of one anchor rod extends and a retainer body disposed in an oblique relation and attached to the tubular mounting body.
U.S. Pat. No. 7,654,773, issued on Feb. 2, 2010 to Bastard et al., provides a system and method for installing a subsea pipeline. An anchor is installed in the seabed and include one or more sheaves. The pipeline is provided with one or more coupling devices situated remotely from the anchor relative to a target area. A winch wire can be provided and is adapted to be directly or indirectly coupled at least a portion of the target area to the pipeline. A transfer sling having a pull wire and an initiation wire can be coupled between the winch wire and pipeline to assist the winch wire so as to pull the pipeline into the target area and transferring a pipeline force from the sheave to the anchor independent of the sheave.
U.S. Patent Publication No. 2010/0142543, published on Jun. 16, 2011 to J. E. Griffin, teaches a method of using a sacrificial pipe string. This method includes lowering a first end of a flowpipe from the vessel. The pipeline end termination is connected to a second end of the flowpipe. A first end of a sacrificial pipe is connected to the pipeline end termination. A winch wire is connected to a second end of the sacrificial pipe. The sacrificial pipe is lowered with the winch wire so that the pipeline end termination rests on the sea floor. The sacrificial pipe is then disconnected from the pipeline end termination.
It is an object of the present invention to provide a pipeline anchoring system which serves to prevent any damage to the pipeline end termination.
It is another object of the present invention to provide a pipeline anchoring system which minimizes the potential of damage to the gas transmission line as a result of excessive forces being applied to the gas pipeline.
It is another object of the present invention to provide a pipeline anchoring system which assures that the gas pipeline will break rather than transmit damaging forces to the pipeline end termination.
It is another object of the present invention to provide a pipeline anchoring system which is easy to install.
It is still a further object of the present invention to provide a pipeline anchoring system in which the pipeline can be anchored through the use of a remotely-operated vehicle.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.